A rack and pinion steering device conventionally used is provided with a casing, a pinion rotatably supported by the casing, a rack bar on which rack teeth to be meshed with said pinion is formed, a rack guide slidably supporting the rack bar and disposed in the casing, a rack guide base member supporting an outer surface of the rack guide and a spring pressing the rack guide toward the rack bar through the rack guide base member (patent literature 1).
The rack guide of the rack and pinion steering device as configured above is a member formed so as to have a curbed surface constituted by a plurality of curvature radiuses to prevent sliding resistance of rack bar from being excessive when the movable rack bar is moved relative to the rack guide. Accordingly, to ensure the rack guide base member to hold the rack guide, a rack guide support surface of the rack guide base member to be abutted to the rack guide is processed so as to have a shape complementary to a curbed surface having a plurality of curvature radiuses similarly to the rack guide.